Source code for evennia.server.webserver

This implements resources for Twisted webservers using the WSGI
interface of Django. This alleviates the need of running e.g. an
Apache server to serve Evennia's web presence (although you could do
that too if desired).

The actual servers are started inside as part of the Evennia

(Lots of thanks to for
a great example/aid on how to do this.)

import urllib.parse
from urllib.parse import quote as urlquote

from django.conf import settings
from django.core.wsgi import get_wsgi_application
from twisted.application import internet
from twisted.internet import defer, reactor
from twisted.python import threadpool
from twisted.web import http, resource, server, static
from twisted.web.proxy import ReverseProxyResource
from twisted.web.server import NOT_DONE_YET
from twisted.web.wsgi import WSGIResource

from evennia.utils import logger

_DEBUG = settings.DEBUG

[docs]class LockableThreadPool(threadpool.ThreadPool): """ Threadpool that can be locked from accepting new requests. """
[docs] def __init__(self, *args, **kwargs): self._accept_new = True threadpool.ThreadPool.__init__(self, *args, **kwargs)
[docs] def lock(self): self._accept_new = False
[docs] def callInThread(self, func, *args, **kwargs): """ called in the main reactor thread. Makes sure the pool is not locked before continuing. """ if self._accept_new: threadpool.ThreadPool.callInThread(self, func, *args, **kwargs)
# # X-Forwarded-For Handler #
[docs]class HTTPChannelWithXForwardedFor(http.HTTPChannel): """ HTTP xforward class """
[docs] def allHeadersReceived(self): """ Check to see if this is a reverse proxied connection. """ if self.requests: CLIENT = 0 http.HTTPChannel.allHeadersReceived(self) req = self.requests[-1] client_ip, port = self.transport.client proxy_chain = req.getHeader("X-FORWARDED-FOR") if proxy_chain and client_ip in _UPSTREAM_IPS: forwarded = proxy_chain.split(", ", 1)[CLIENT] self.transport.client = (forwarded, port)
# Monkey-patch Twisted to handle X-Forwarded-For. http.HTTPFactory.protocol = HTTPChannelWithXForwardedFor
[docs]class EvenniaReverseProxyResource(ReverseProxyResource):
[docs] def getChild(self, path, request): """ Create and return a proxy resource with the same proxy configuration as this one, except that its path also contains the segment given by path at the end. Args: path (str): Url path. request (Request object): Incoming request. Return: resource (EvenniaReverseProxyResource): A proxy resource. """ request.notifyFinish().addErrback( lambda f: 0 # lambda f: logger.log_trace("%s\nCaught errback in" % f) ) return EvenniaReverseProxyResource(, self.port, self.path + "/" + urlquote(path, safe=""), self.reactor )
[docs] def render(self, request): """ Render a request by forwarding it to the proxied server. Args: request (Request): Incoming request. Returns: not_done (char): Indicator to note request not yet finished. """ # RFC 2616 tells us that we can omit the port if it's the default port, # but we have to provide it otherwise, 0) qs = urllib.parse.urlparse(request.uri)[4] if qs: rest = self.path + "?" + qs.decode() else: rest = self.path rest = rest.encode() clientFactory = self.proxyClientFactoryClass( request.method, rest, request.clientproto, request.getAllHeaders(),, request, ) clientFactory.noisy = False self.reactor.connectTCP(, self.port, clientFactory) # don't trigger traceback if connection is lost before request finish. request.notifyFinish().addErrback(lambda f: 0) # request.notifyFinish().addErrback( # lambda f:logger.log_trace("Caught errback in %s" % f) return NOT_DONE_YET
# # Website server resource #
[docs]class DjangoWebRoot(resource.Resource): """ This creates a web root (/) that Django understands by tweaking the way child instances are recognized. """
[docs] def __init__(self, pool): """ Setup the django+twisted resource. Args: pool (ThreadPool): The twisted threadpool. """ self.pool = pool self._echo_log = True self._pending_requests = {} super().__init__() self.wsgi_resource = WSGIResource(reactor, pool, get_wsgi_application())
[docs] def empty_threadpool(self): """ Converts our _pending_requests list of deferreds into a DeferredList Returns: deflist (DeferredList): Contains all deferreds of pending requests. """ self.pool.lock() if self._pending_requests and self._echo_log: self._echo_log = False # just to avoid multiple echoes msg = "Webserver waiting for %i requests ... " logger.log_info(msg % len(self._pending_requests)) return defer.DeferredList(self._pending_requests, consumeErrors=True)
def _decrement_requests(self, *args, **kwargs): self._pending_requests.pop(kwargs.get("deferred", None), None)
[docs] def getChild(self, path, request): """ To make things work we nudge the url tree to make this the root. Args: path (str): Url path. request (Request object): Incoming request. Notes: We make sure to save the request queue so that we can safely kill the threadpool on a server reload. """ path0 = request.prepath.pop(0) request.postpath.insert(0, path0) request.notifyFinish().addErrback( lambda f: 0 # lambda f: logger.log_trace("%s\nCaught errback in" % f) ) deferred = request.notifyFinish() self._pending_requests[deferred] = deferred deferred.addBoth(self._decrement_requests, deferred=deferred) return self.wsgi_resource
# # Site with deactivateable logging #
[docs]class Website(server.Site): """ This class will only log http requests if settings.DEBUG is True. """ noisy = False
[docs] def logPrefix(self): "How to be named in logs" if hasattr(self, "is_portal") and self.is_portal: return "Webserver-proxy" return "Webserver"
[docs] def log(self, request): """Conditional logging""" if _DEBUG: server.Site.log(self, request)
# # Threaded Webserver #
[docs]class WSGIWebServer(internet.TCPServer): """ This is a WSGI webserver. It makes sure to start the threadpool after the service itself started, so as to register correctly with the twisted daemon. call with WSGIWebServer(threadpool, port, wsgi_resource) """
[docs] def __init__(self, pool, *args, **kwargs): """ This just stores the threadpool. Args: pool (ThreadPool): The twisted threadpool. args, kwargs (any): Passed on to the TCPServer. """ self.pool = pool super().__init__(*args, **kwargs)
[docs] def startService(self): """ Start the pool after the service starts. """ try: super().startService() self.pool.start() except Exception: logger.log_trace("Webserver did not start correctly. Disabling.") self.stopService()
[docs] def stopService(self): """ Safely stop the pool after the service stops. """ try: super().stopService() except Exception: logger.log_trace("Webserver stopService error.") finally: if self.pool.started: self.pool.stop()
[docs]class PrivateStaticRoot(static.File): """ This overrides the default static file resource so as to not make the directory listings public (that is, if you go to /media or /static you won't see an index of all static/media files on the server). """
[docs] def directoryListing(self): return resource.ForbiddenResource()